Below is the API for the OCaml standard library. It's directly copied over from the OCaml Manual, formatted to the Reason syntax and styled accordingly. The API docs are work-in-progress; we'll be polishing these gradually!
If you're targeting JavaScript, the API docs for BuckleScript includes all of below, plus JS-specific APIs.
sig module type OrderedType = Set.OrderedType module type S = sig type elt and t val empty : MoreLabels.Set.S.t val is_empty : MoreLabels.Set.S.t -> bool val mem : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t -> bool val add : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val singleton : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t val remove : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val union : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val inter : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val diff : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val compare : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> int val equal : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> bool val subset : MoreLabels.Set.S.t -> MoreLabels.Set.S.t -> bool val iter : f:(MoreLabels.Set.S.elt -> unit) -> MoreLabels.Set.S.t -> unit val fold : f:(MoreLabels.Set.S.elt -> 'a -> 'a) -> MoreLabels.Set.S.t -> init:'a -> 'a val for_all : f:(MoreLabels.Set.S.elt -> bool) -> MoreLabels.Set.S.t -> bool val exists : f:(MoreLabels.Set.S.elt -> bool) -> MoreLabels.Set.S.t -> bool val filter : f:(MoreLabels.Set.S.elt -> bool) -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t val partition : f:(MoreLabels.Set.S.elt -> bool) -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t * MoreLabels.Set.S.t val cardinal : MoreLabels.Set.S.t -> int val elements : MoreLabels.Set.S.t -> MoreLabels.Set.S.elt list val min_elt : MoreLabels.Set.S.t -> MoreLabels.Set.S.elt val max_elt : MoreLabels.Set.S.t -> MoreLabels.Set.S.elt val choose : MoreLabels.Set.S.t -> MoreLabels.Set.S.elt val split : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t -> MoreLabels.Set.S.t * bool * MoreLabels.Set.S.t val find : MoreLabels.Set.S.elt -> MoreLabels.Set.S.t -> MoreLabels.Set.S.elt val of_list : MoreLabels.Set.S.elt list -> MoreLabels.Set.S.t end module Make : functor (Ord : OrderedType) -> sig type elt = Ord.t and t val empty : t val is_empty : t -> bool val mem : elt -> t -> bool val add : elt -> t -> t val singleton : elt -> t val remove : elt -> t -> t val union : t -> t -> t val inter : t -> t -> t val diff : t -> t -> t val compare : t -> t -> int val equal : t -> t -> bool val subset : t -> t -> bool val iter : f:(elt -> unit) -> t -> unit val fold : f:(elt -> 'a -> 'a) -> t -> init:'a -> 'a val for_all : f:(elt -> bool) -> t -> bool val exists : f:(elt -> bool) -> t -> bool val filter : f:(elt -> bool) -> t -> t val partition : f:(elt -> bool) -> t -> t * t val cardinal : t -> int val elements : t -> elt list val min_elt : t -> elt val max_elt : t -> elt val choose : t -> elt val split : elt -> t -> t * bool * t val find : elt -> t -> elt val of_list : elt list -> t end end